RÉSUMÉ
OBJECTIVE: To estimate the cost-effectiveness of online behavioral interventions (EczemaCareOnline.org.uk) designed to support eczema self-care management for parents/carers and young people from an NHS perspective. METHODS: Two within-trial economic evaluations, using regression-based approaches, adjusting for baseline and pre-specified confounder variables, were undertaken alongside two independent, pragmatic, parallel group, unmasked randomized controlled trials, recruiting through primary care. Trial 1 recruited 340 parents/carers of children aged 0-12 years and Trial 2 337 young people aged 13-25 years with eczema scored ≥ 5 on Patient-Oriented Eczema Measure (POEM). Participants were randomized (1:1) to online intervention plus usual care or usual care alone. Resource use, collected via medical notes review, was valued using published unit costs in UK £Sterling 2021. Quality-of-life was elicited using proxy CHU-9D in Trial 1 and self-report EQ-5D-5L in Trial 2. RESULTS: The intervention was dominant (cost saving and more effective) with a high probability of cost-effectiveness (> 68%) in most analyses. The exception was the complete case cost-utility analysis for Trial 1 (omitting participants with children aged < 2), with adjusted incremental cost savings of -£34.15 (95% CI - 104.54 to 36.24) and incremental QALYs of - 0.003 (95% CI - 0.021 to 0.015) producing an incremental cost per QALY of £12,466. In the secondary combined (Trials 1 and 2) cost-effectiveness analysis, the adjusted incremental cost was -£20.35 (95% CI - 55.41 to 14.70) with incremental success (≥ 2-point change on POEM) of 10.3% (95% CI 2.3-18.1%). CONCLUSION: The free at point of use online eczema self-management intervention was low cost to run and cost-effective. TRIAL REGISTRATION: This trial was registered prospectively with the ISRCTN registry (ISRCTN79282252). URL www.EczemaCareOnline.org.uk .